Marine jet propulsion system

ABSTRACT

This invention relates to the ahead-and-astern propulsion of marine vessels by means of a reversible hydraulic-jet ejector structure composed in part of oppositely-directed ejector stagings disposed centrally within a longitudinal open-channel conduit formed into the vessel&#39;&#39;s hull. The open-channel conduit is formed by opposite chines or keels which depend downwardly from the bottom hull structure of the vessel to define boundaries of the longitudinal ejector passage. A pivoted secondary-nozzle member is disposed centrally within the after section of the longitudinal ejector passage to steer the vessel in ahead propulsion. The invention includes motive-fluid piping systems for supplying pressurized motive fluids to motive nozzles of the reversible ejector structure from liquid pumps, pressurized steam and water from displacement pressure vessels of pulse-jet systems, and pressurized steam from saline conversion power plants for condensing steam jets within the longitudinal ejector passage of the reversible ejector structure. The invention also includes independent liquid pulse-jet and steam-jet propulsion systems.

[ Dec. 18, 1973 Hull [ 1 MARINE JET PROPULSION SYSTEM [76] Inventor: Francis R. Hull, 567 E. 26th St.,

Brooklyn, NY. 11210 [22] Filed: Sept. 22, 1971 [21] Appl. No.: 182,760

Related U.S. Application Data [63] Continuation-impart of Ser. No. 701,262, Dec. 6, 1957, abandoned, Continuation-in-part of Serv No. 277,071, April 29, 1963, abandoned, Continuation'in-part of Ser. No. 353,700, March 23, 1964, abandoned, Continuation-impart of Ser. No. 492,959, Aug. 27, 1965, abandoned, Continuation-in-part of Ser. No. 554,614, April 27, 1966, abandoned, Continuation-impart of Ser. No. 666,234, Aug. 9, 1967, abandoned, Continuation-in-part of Ser. No. 732,476, April 25, 1968, abandoned, Continuation-in-part of Ser. No. 814,475, Feb. 17, 1969, Pat. No. 3,620,183.

[52] U.S. CI ..115/l6,l14/l5l, 115/14 [51] Int. Cl B6311 11/12 [58] Field of Search 60/221; 239/95;

[56] References Cited UNITED STATES PATENTS 1,665,053 4/1928 Carpio 115/14 1,023,205 4/1912 Jensen 115/14 1,375,601 4/1921 Morize 115/11 X 3,209,717 10/1965 Campbell et a1 114/151 1,676,150 7/1928 Mawby 115/12 R X 2,363,335 11/1944 Katcher et a1. 114/151 X FOREIGN PATENTS OR APPLICATIONS 2,502 8/1868 Great Britain 115/14 Primary Examiner-Milton Buchler Assistant Examiner-Stephen G. Kunin Atl0rney-Robert U. Geib, Jr.

57 ABSTRACT This invention relates to the ahead-and-astern propulsion of marine vessels by means of a reversible hydraulic-jet ejector structure composed in part of oppositely-directed ejector stagings disposed centrally within a longitudinal open-channel conduit formed into the vessels hull. The open-channel conduit is formed by opposite chines or keels which depend downwardly from the bottom hull structure of the vessel to define boundaries of the longitudinal ejector passage. A pivoted secondary-nozzle member is disposed centrally within the after section of the longitudinal ejector passage to steer the vessel in ahead propulsion. The invention includes motive-fluid piping systems for supplying pressurized motive fluids to motive nozzles of the reversible ejector structure from liquid pumps, pressurized steam and water from displacement pressure vessels of pulse-jet systems, and pressurized steam from saline conversion power plants for condensing steam jets within the longitudinal ejector passage of the reversible ejector structure. The invention also includes independent liquid pulse-jet and steam-jet propulsion systems.

18 Claims, 9 Drawing Figures SHEEI 2 0F 2 PATENTEU DEC 1 8 I975 INVENTOR. Francis R.Hu|l

Wu. w 9b.

ATTORNEY PAIENTED on: 18 1915 SHEET 1 IF 2 3 3 m; 3 0 m; 3 i m; w III R 7 g v6} 3 i "1 MR VS l Wm Q mi Q v mi m F m? m me i 0 ATTORNEY MARINE JET PROPULSION SYSTEM The present application is a continuation-in-part of my patent application, Ser. No. 701,262 entitled Jet Reaction Tube Structure for Marine Propulsion, filed Dec. 6, 1951 (now abandoned); my patent application, Ser. No. 277,071 entitled Marine Jet Propulsion System, filed Apr. 29, 1963 (now abandoned); my patent application, Ser. No. 353,700 entitled Marine Jet Propulsion System, filed Mar. 23, 1964 (now abandoned); my patent application, Ser. No. 492,959 entitled Marine Jet Propulsion System, filed Aug. 27, 1965 (now abandoned); my patent application, Ser. No. 554,614 entitled Marine Jet Propulsion System, filed Apr. 27, 1966 (now abandoned); my patent application, Ser. No. 666,234 entitled Marine Jet Propulsion System, filed Aug. 9, 1967 (now abandoned); my patent application, Ser. No. 732,476 entitled Marine Jet Propulsion System, filed Apr. 25, 1968 (now abandoned); and my patent application, Ser. No. 814,475 entitled Marine Jet Propulsion System, filed Feb. 17, 1969, now US Pat. No. 3,620,183 issued Nov. 16, 1971.

The invention includes as propelling means a reversible hydraulic-jet ejector structure composed in part of oppositely directed thrust-augmenting secondarynozzle ejector stagings disposed centrally within a longitudinal open-channel conduit formed by opposite chines or keels which depend downwardly from the hull structure of the marine vessel. The after end of this complex ejector passage may be warped or flared into an effective diffuser section, to reduce fluid friction and provide location for a pivoted steering nozzle used in ahead propulsion. The invention also includes several independent propulsion systems which may be used to supply pressurized motive fluids to any hydraulic-jet propulsion system, or to motive nozzles of the reversible hydraulic-jet ejector structure.

A principal object of the invention is to provide novel propulsive means which eliminate mechanical energy conversion from the propulsion power train of major marine vessels, and which are feasible alternatives to conventional propeller-type propulsion systems.

Another object is to provide alternate means to the conventional rudder for steering a hydraulic-jet propelled marine vessel in ahead propulsion. the term open conduit shall refer to a channel or trough having a non-continuous peripheral cross section used for guiding the flow of fluids which are exposed to the pressure of ambient surroundings;

the term closed conduit shall refer to a tube, pipe or duct having a continuous peripheral cross section which is capable of conveying fluids with pressures which are substantially different from that of its ambient exterior surroundings;

the term open-channel conduit shall relate to the exposed longitudinal ejector passage of the reversible hydraulic-jet ejector structure used to facilitate aheadand-astern propulsion of marine vessels; structure with advantage.

As used herein: the term fluid shall refer to any liquid or gaseous medium; the term reversible shall relate to marine propulsion system which may direct its propelling fluid discharge with comparable facility in opposite directions;

the term motive fluid shall refer to the fluid piping system which actuates a propulsion reaction;

the term suction fluid shall refer to the fluid which is being accelerated by contact with a highervelocity fluid stream; the term ejector passage shall include the configuration of nozzle passageways within an ejector structure which guide the acceleration of suction fluids;

the term ejector staging shall relate to an ejector structure composed of a motive nozzle and one or more secondary nozzles disposed in tandem with respect to each other down-stream of the motive nozzle so that an upstream nozzle member discharges its fluid jet into the central bore of the next downstream nozzle member, and each secondarynozzle member is disposed to admit suction fluids thereinto from the direction of positive diflerential pressure;

the term hydraulic-jet propulsion shall refer to a marine propulsion system which develops propelling thrusts by taking in water at a convenient point and accelerating the liquid stream through its propulsor;

For a mobile vehicle which is propelled by the acceleration of fluids surrounding the vehicle, and where the intake of the fluid being accelerated through the propulsor is directed opposite the direction of final discharge, propulsion efficiency is given by the expression:

E (2 V,)/( V +V,,) (E approaches percent as V, approaches V Where:

V, is the absolute velocity of the vehicle; and V is the absolute final velocity of the propelling fluid leaving the propulsion system in the direction of final discharge; Maximum theoretical propulsion efficiency in this case is limited to 100 percent. In a practical sense the highest propulsive efficiencies are attained where the maximum of fluid kinetic energy has been converted to propulsive thrust, and final discharge velocities relative to the vessel are very low.

With the declared objects in view together with others which will emerge as the description proceeds, the invention resides in the novel construction, assemblage and arrangement of elements which will be described more fully in the discussion, illustrated in the drawings, and particularly pointed out in the claims.

In the drawings:

FIG. 1 is a partially segmented longitudinal sectional view of a semi-planing type of marine vessel which is propelled in the fore-and-aft direction by a reversible hydraulic-jet ejector structure formed in the novel hull structure of the vessel.

FIG. 2 is a longitudinal sectional view of the segmented reversible hydraulic-jet ejector structure taken along broken line AA of FIG. 1.

FIG. 3 is a transverse sectional view of the ship structure substantially taken along line 8-8 of FIG. 1.

FIG. 4 is a transverse sectional view of the ship structure substantially taken along line C-C of FIG. 1.

FIG. 5 is a transverse sectional view of the ship structure substantially taken along line DD of FIG. 1.

FIG. 6 is a transverse sectional view of the ship structure substantially taken along line EE of FIG. 1.

FIG. 7 is a line isometric schematic diagram of a simplified pulse-type of hydraulic-jet propulsion system wherein oppositely-directed propulsion nozzles 25 and 30 may be alternately supplied with pressurized motive fluids from multiple displacement cylinders 35 which are actuated by pressurized steam from a common source.

FIG. 8 is a line isometric schematic diagram of a simplified steam-jet propulsion system wherein oppositely directed propulsion nozzles 56 and 63 may be alter nately supplied with pressurized motive steam from a saline conversion type of power plant. The saline conversion power plant may continuously receive and evaporate raw saline feed water while rejecting salts and other impurities therefrom.

FIG. 9 is a line isometric schematic diagram of a simplified hydraulic-jet propulsion system wherein oppositely directed propulsion nozzles 85 and 911 may be alternately supplied with pressurized water from a mechanical pump. The hydraulic-jet propulsion system of this view receives intake fluids from the direction of positive differential pressure through intake scoop 95 when propelling the vessel ahead by discharging from ahead propulsion nozzle 85.

The invention includes an arrangement upon the marine vessel of a novel longitudinally disposed openchannel conduit formed by opposite chines or keels which depend downwardly from the hull structure. Oppositely-directed secondary-nozzle ejector stagings are centrally disposed in the submerged longitudinal open conduit to develop propulsive thrust in either propelling direction by discharging towards adjacent ends of the conduit. An ejector staging is comprised of a motive nozzle together with one or more secondary nozzles having substantial frusto-conical shape disposed downstream of the primary motive nozzle, so that an upstream nozzle member of the staging discharges its fluid jet into the central bore of the adjacent downstream secondary-nozzle member which accelerates additional suction fluid through the structure and develops additional thrust to augment that developed by upstream nozzle members of the ejector staging. The enlarged entrance of each secondary-nozzle member is disposed to admit suction fluids thereinto from the direction of positive differential pressure when the vessel is being propelled by that secondary-nozzle members ejectorstaging. Secondary-nozzle members of an ejector staging would normally have a convergent configuration to channel the flow of suction fluid into a reduced throat section where mixing and momentum interchange with the motive-fluid jet stream occurs. An ejector staging may be actuated by any suitable pressurized motive fluid such as water or steam, which would usually be supplied from a motive-fluid power system within the vessel. The combination of the submerged longitudinal open conduit, oppositely directed thrust-augmenting secondary-nozzle ejector stagings and means for supplying pressurized motive fluids to the primary motive nozzles of each ejector staging comprise a reversible jet-reaction ejector structure which is the principal propulsor of the marine vessel. The hereinbefore referred to reversible jet-reaction ejector structure for marine propulsion is, in its broadest sense described in my aforementioned parent patent application Ser. No. 814,475 now U.S. Pat. No. 3,620,183 issued Nov. 16, 1971.

The after end of the submerged longitudinal open conduit may be warped or flared into an effective diffuser section adjacent the discharge of the forward propulsion ejector staging. This modification is illustrated in the embodiment of FIG. 2.

The vessel may be steered in ahead propulsion by means of a pivoted steering nozzle. As shown in FIGS. 1, 2 and 3, the steering nozzle may be located centrally in the after end of the submerged conduit and disposed to rotate about a vertical axis. When the vessel has headway, waters from the after end of submerged ejector passage 16 are partially diverted into the large elliptical steering nozzle 21. When nozzle 21 is rotated about a vertical axis through an angular displacement in either direction from the foreand-aft centerline, waters accelerated therethrough develop a substantial unbalanced thrust which reacts on the nozzle and the vessels stern. The lateral component of this unbalanced thrust acts about the vessels turning center to produce a moment about the vertical which alters the vessels course.

The segmented semi-planing vessel shown in FIG. 11 may also be maneuvered by thrusting effects developed by laterally disposed submerged reaction tubes 24. Operation of the maneuvering variation of the reversible jet-reaction ejector structure per se is described in the parent patent application, Ser. No. 814,475 new U.S. Pat No. 3,620,183 issued Nov. 16, 1971.

Pressurized motive fluids supplied to actuate the reversible hydraulic jet ejector structure may be either water or steam. Pressurized water may be supplied to motive nozzles of the reversible ejector structure either from mechanical pumps, or from displacement-type pressure vessels which are operated by steam pressure. Pressurized steam may be supplied to motive nozzles of the reversible ejector structure from a saline conversion power plant which evaporates raw feedwater from waters in which the vessel navigates while rejecting salts and other impurities therefrom.

Pressurized water may be supplied directly to motive nozzles 18 and 22 (FIGS. 1 and 2) of the reversible jetreaction ejector structure. The vessel would then be substantially propelled by the total summation of thrusts developed by the primary motive nozzle and the secondary-nozzle membersof an ejector staging. Total thrust developed by an ejector staging would be limited by the quantity of motive-fluid kinetic energy supplied by the motive nozzle, and total thrust may be expressed as a function of motive-fluid power injected by the motive nozzle.

Due to its kinetic energy, the region of the motivewater jet stream is at a lower pressure than the surrounding suction fluid. As caused by absolute pressure at the level of the motive nozzle, suction fluids will continuously move into the low-pressure region of the motive-water jet stream. The flow of suction fluids into the low-pressure region of the motive-water jet stream would be channeled from the direction of positive differential pressure by the configuration of secondarynozzle members 19 and 20 adjacent the discharge of motive nozzle 18. As the vessel gained speed, hydraulic-ram pressure effects derived from vessel motion would cause increased suction fluid pressure in regions adjacent the enlarged entrances of secondary-nozzle members 19 and 20. These hydraulic-ram pressure effects would increase the entrainment of suction fluid into the region of the high-velocity motive-water jet stream issuing from motive nozzle 18.

Pressurized steam may be supplied directly to motive nozzles 18 and 22 (FIGS. 1 and 2) of the reversible jetreaction ejector structure. The vessel would then be substantially propelled by displacement effects of secondary suction fluid flowing into the region of the condensing motive steam jet. Under effects of the absolute pressure at the level of the motive nozzle, displacement suction fluid would continuously attempt to displace the difference in volumes caused by state change of the motive steam. The displacement suction fluid would substantially flow into the region of the condensing motive-steam jet stream discharged by motive nozzle 18 from the direction of positive differential pressure when the vessel was being propelled by ejector staging 18-20 inclusive. Similarly when motive-nozzle member 22 discharges a high-velocity condensing steam jet into secondary-nozzle member 23, displacement suction fluid flowing into the region of the condensing steam jet must come substantially from the direction of positive differential pressure. This channeling of displacement suction fluid into enlarged entrances of secondarynozzle members adjacent their motive nozzles on the downstream side is caused by the configuration of the respective secondary-nozzle member itself, and by the configuration of adjacent conduit boundaries formed by downward depending chine or keel members.

The greatest displacement reaction (and thrust development) caused by effects of suction fluid flowing into the region of the condensing motive-steam jet would occur where the change in specific volume was greatest, and where condensation of the motive steam jet was most rapid. The magnitude of suction fluid displacement reaction would be substantially affected by changes in the following:

a. Increased motive-steam injection temperature with increased specific volume;

b. Increased motive-steam injection velocity caused by increased steam supply pressure with more rapid steam-jet condensation;

c. Decreasing sea temperature with more rapid condensation of the motive steam jet;

d. Increased vessel speed with increased hydraulicram pressure effects at the entrances of secondarynozzle members which also increase the quantity and velocity of suction fluid movement into the region of a condensing steam jet.

FIG. 1 depicts the general outline of a segmented and sectional view of a semi-planing type of marine vessel which is propelled in the fore-and-aft direction by a reversible hydraulic-jet ejector structure. The marine vessel shown in FIG. 1 is comprised of aft-body section 11 having any appropriate length (shown in partial longitudinal center section), mid-body section 12 of any appropriate length (shown in a full-section exterior view), and fore-body section 13 of any appropriate length (shown in partial longitudinal center section). A submerged fore-and-aft ejector passage 16 is disposed below the normal waterline and defined in the bottom hull structure of downwardly depending marine vessel 11-13 inclusive by the boundaries of left-side or port keel member 14 and right-side or starboard keel member 15. Suitably disposed within submerged longitudinal open conduit 16 and supported from the vessels hull structure by any suitable structural members are oppositely directed secondary-nozzle ejector stagings 18-20 and 22-23 inclusive, which each discharge towards their respective adjacent propelling ends of ejector passage 16. Ahead propulsion ejector staging 18-20 inclusive discharges towards the adjacent after end of ejector passage 16 and is comprised of motive nozzle 18, 1st stage secondary-nozzle member 19, and 2nd stage secondary-nozzle member 20. Astern propulsion ejector staging 22-23 inclusive discharges towards the adjacent forward end of ejector passage 16 and is comprised of motive nozzle 22 and secondary-nozzle member 23. The after section of submerged longitudinal open conduit 16 within the vessel aft-body section 11 may be warped or flared into an effective diffuser section adjacent the discharge of forward propulsion ejector staging 18-20, by altering the configuration of downwardly depending keel members 14 and 15 as shown in FIG. 2. Motive nozzle 18 of forward propulsion ejector staging 18-20 and motive nozzle 22 of astern propulsion ejector staging 22-23 may be alternately supplied with pressurized motive fluid from within the vessel by any appropriate means.

Arranged centrally within the diffuser section of submerged conduit 16 is pivoted steering nozzle 21, which is disposed to rotate about a vertical axis as shown in FIGS. 1-3 inclusive. The angular position of steering nozzle 21 with respect to its fore-and-aft axis in longitudinal open conduit 16 is controlled by steering machinery housed within the vessel, such as is presently common in the marine engineering arts. Elliptical steering nozzle 21 may be further stabilized in its vertical orientation by additional structural struts or braces (not shown) as may be required for structural stability.

In ahead propulsion, motive intake fluid consisting of waters from within submerged ejector passage 16 enters ahead propulsion intake scoop 17 from the direction of positive differential pressure. The orientation of intake scoop 17 towards the direction of positive differential pressure is necessary for reasons of propulsion efficiency in ahead propulsion, as explained heretofore. If the intake of motive intake fluids from waters outside the vessel into the motive-fluid power system were from some other direction, pumping machinery within the vessel would be required to perform unnecessary work in ahead propulsion to accelerate fluid particles of the motive intake-fluid stream to vessel speed in the direction of propulsion. Because most vessel operations are likely to be in ahead propulsion, the disposition of ahead propulsion intake scoop 17 is important.

In astern propulsion, motive intake fluid consisting of waters from within submerged ejector passage 16 or elsewhere may enter the motive-fluid piping system from a vertically-disposed suction pipe in any convenient location (Not shown in FIGS. 1 and 2). Since the vessel would normally have but limited operation in astern propulsion, considerations of propulsion efficiency are not as demanding as in ahead propulsion.

The vessel may be propelled laterally in either direction, or turned about a vertical axis in either direction by thrusts developed in submerged maneuvering tubes 24. Submerged maneuvering tubes 24 are located at the fore-and-aft ends of the vessel as shown in FIG. 1. Laterally disposed maneuvering tubes 24 are reversible jet-reaction ejector structures whichmay develop controllable lateral thrusts with equal facility in opposite directions and their operation has been fully described in parent patent application, Ser. No. 814,475 now U.S. Pat. No. 3,620,183 issued Nov. 16, l97l.

FIG. 7 is a line isometric schematic diagram in simplified form of a pulse-jet type of hydraulic-jet propulsion system wherein a saline conversion power plant or other suitable steam source may alternately supply pressurized steam to force the discharge of motive sea water from either of displacement cylinders 35 into supply piping which communicates with either of propulsion nozzles and 30. As shown by the exterior arrow at the left-hand side of FIG. 7, motive sea water enters intake scoop or sea chest 47 from the direction of positive differential pressure while the entire structure (and the marine vessel) is being propelled to the left and into the drawing by reactions to the discharge of high-velocity motive fluids from ahead propulsion nozzle 25 at the right-hand side of the figure.

Motive sea water enters intake scoop or sea chest 47 in the left background, and flows into suction main 45 through sea valve 46. The motive sea water flows past closed filling valve 40 of the near displacement cylinder into suction intake branch 39 of the far displacement cylinder by way of filling valve and check valve 41. The motive sea water rapidly gravitates into the low-pressure vacuum space within the far displacement cylinder 35 caused by cooling-water jet spray 51, which causes the condensation of spent steam therewithin. A suitable jet-spray attachment would be provided within each displacement cylinder 35 which is supplied with pressurized cooling water from water supply main 44, individual supply branch 42 and individual supply valve 43. The discharge valve 34 of the far left-hand displacement cylinder 35 would be closed during these simultaneous filling and condensing operations.

The near right-hand displacement cylinder 35 in FIG. 7 is being supplied with high-pressure steam from any suitable steam source, which forces the discharge of motive sea waters therefrom. High-pressure steam from steam supply main 38 flows past closed steam valve 37 of the far displacement cylinder into the near displacement cylinder 35 through its individual steam supply branch 36 by way of open steam valve 37. The highpressure steam acts principally on the surface of the motive sea water within the near displacement cylinder to force the discharge thereof as indicated by the exterior arrows. The pressurized motive fluid is discharged through cylinder discharge line 32 by way of its open discharge valve 34 and check valve 33. During the discharge of pressurized motive fluids from either displacement cylinder, the respective cooling water supply valve 43 and filling check valve 41 are closed.

The pressurized motive fluid flows from discharge branch 32 of the pressurized displacement cylinder 35 which is discharging into motive-fluid supply main 28 communicates with supply branch 26 of ahead propulsion nozzle 25 by way of supply valve 27, and supply branch 29 of astem propulsion nozzle 30 by way of supply valve 31. When motive fluid is being discharged from ahead propulsion nozzle 25 by way of open supply valve 27, the alternate supply valve 31 of oppositely directed astern propulsion nozzle 30 would normally be closed off.

A vertically disposed overboard discharge line 52 communicates with motive-fluid discharge main 28. Pressurized motive fluids from the multiple displacement cylinders 35 may then be alternately discharged from discharge main 28 into overboard discharge line 52 through discharge valve 53, check valve 54 and thence downwards through bottom discharge flange 55. This arrangement permits standby operation of the selected pulse-jet system without exerting propulsive thrusts on the vessel.

In astern propulsion, motive sea water would normally enter the motive fluid piping system of FIG. 7 through vertically-disposed bottom intake branch 48 by way of bottom inlet flange 50 and bottom intake valve 49. Alternate filling and discharge of multiple displacement cylinders 35 would then proceed as in ahead propulsion. Considerations of propulsion efficiency in astem propulsion would not ordinarily require a separate intake scoop directed against positive differential pressure, since the astern propulsion mode has much lesser application than ahead propulsion.

Displacement cylinders 35 may normally be filled by gravitation of outside sea water into the low-pressure vacuum space within each cylinder caused by condensation of spent steam. Displacement cylinders 35 would normally be located on the lower levels of vessel machinery spaces to provide the maximum absolute pressure differential for filling operations. A fluid pump may be disposed in motive sea water filling main 45 to assist in filling operations as required in a particular systems application.

The saline conversion type of steam-jet propulsion system in simplified form of FIG. 8 processes raw feedwater taken from waters in which the vessel navigates, evaporates the raw feedwater to steam while rejecting salts and other impurities therefrom, and supplies pressurized steam to oppositely directed ahead and astem propulsion nozzles. As shown by the exterior arrow at the right background of FIG. 8, motive feedwater enters intake scoop or sea chest from the direction of positive differential pressure while the entire structure (and the marine vessel) is being propelled to the left and into the drawing by reactions to the high-velocity motive-steam jet being discharged from ahead propulsion nozzle 56 in the left foreground of the figure.

Raw feedwater enters intake scoop or sea chest 70 in the right background, and flows into pump suction main 68 by way of open sea valve 69. The raw feedwater flows past closed bottom intake valve 72 into the suction of feed pump 67. The raw feedwater is pressurized by feed pump 67 and discharged into saline evaporator 64 by way of pump feed main 65 and feed valve 66.

Saline evaporator 64 receives heat energy from liquid metals heat exchanger 79 or other heat source. A liquid metals heat exchanger '79 may be included which is supplied with heat energy from a primary heat source, such as a nuclear reactor. Heat energy is rapidly transferred from liquid metals heat exchanger 79 to saline evaporator 64 in a forced convection process by circulating pump 82. Circulating pump 82 receives cooled liquid metals from the internal heat transfer processes of saline evaporator 64 through circulating suction line 83 by way of suction valve 84. The pressurized liquid metals leave pump 82 and are discharged into liquid metals heat exchanger 79 by way of circulating discharge line 80 and valve 81. High-temperature liquid metals flow from the internal heating processes of liquid metal heat exchanger 79 through circulating supply main 78 to the internal heat transfer processes of saline evaporator 64. Cooled liquid metals flow from saline evaporator 64 into circulating suction line 83, and the heat transfer cycle is repeated. Salts and other impurities are discharged from the internal processes of saline evaporator 64 into overboard discharge line 74, and flow past discharge valve and check valve 76. The

rejected salts and impurities are then discharged overboard through bottom flange fitting 77.

Pressurized motive steam flows from saline evaporator 64 into nozzle supply main 59 by way of valve 60. The pressurized motive steam may be discharged from supply main 59 into either ahead propulsion nozzle 56 by way of ahead steam supply branch 57 and nozzle valve 58, or into astern propulsion nozzle 63 by way of astern steam supply branch 61 and nozzle valve 62.

In astern propulsion, feed pump 67 may take suction from bottom intake branch 71 by way of bottom inlet flange 73 and bottom intake valve 72. Since astern propulsion normally has relatively little use as compared with ahead propulsion, considerations of propulsion efficiency would not usually require an intake scoop adapted to receive suction fluids from the direction of positive differential pressure.

FIG. 9 is a line isometric schematic diagram in simplified form of a common hydraulic-jet propulsion system which is mechanically actuated by a liquid pump. As shown by the exterior arrow at the left background of FIG. 9, motive sea water enters intake scoop or sea chest 95 from the direction of positive differential pressure while the entire structure (and the marine vessel) is being propelled to the left and into the drawing by reactions to the high-velocity water jet being discharged from ahead propulsion nozzle 85 in the right foreground of the figure.

Motive sea water enters intake scoop or sea chest 95 in the left background and flows into suction branch 93 by way of sea valve 94, and flows on past closed bottom intake valve 97 into the suction of pump 92. The motive sea water is pressurized by pump 92, and discharged into motive-fluid distribution header 88. The pressurized motive fluid may be discharged from distribution header 88 into either ahead propulsion nozzle 85 by way of ahead nozzle supply branch 86 and nozzle valve 87, or into astern propulsion nozzle 91 by way of astern nozzle supply branch 89 and nozzle valve 90.

In astern propulsion, pump 92 may take suction from bottom intake branch 96 by way of bottom inlet flange 98 and bottom intake valve 97. Since astern propulsion is used much less than ahead propulsion in most propulsion system applications, considerations of propulsion efficiency would not usually require an intake scoop adapted to receive pump suction fluids from the direction of positive differential pressure.

It should be understood that either of the simplified reversible hydraulic-jet propulsion systems disclosed in the illustrative embodiments of FIGS. 7 and 9 may propel a marine vessel independently of the reversible hydraulic-jet ejector structure disclosed in FIGS. 1-6 inclusive. Similarly the simplified reversible steam-jet propulsion system disclosed in the illustrative embodiment of FIG. 8 may propel a marine vessel independently of the reversible hydraulic-jet ejector structure disclosed in FIGS. 1-6 inclusive. Conversely, any of the propulsion systems disclosed in FIGS. 7, 8 and 9 may be conveniently adapted to supply pressurized motive fluids to the reversible hydraulic-jet ejector structure disclosed in FIGS. 1-6 inclusive of the present application.

Conventional propeller-driven marine vessels find it difficult to stop quickly, especially when they are heavily laden and propelled ahead under full power. Even after rotation of the propeller has been reversed under full power, these vessels normally travel ahead for at least several nautical miles before their momenta are counteracted.

When the hydraulic-jet propelled marine vessel has headway and motive nozzle 18 is shut off, sea water flowing in the longitudinal open conduit of the reversible ejector structure exerts substantial drag forces on secondary-nozzle members 19 and 20 in the astern direction. When the marine vessel has sternway and motive nozzle 22 is shut off, sea water flowing in the longitudinal open conduit of the reversible ejector structure exerts substantial drag forces on secondary-nozzle member 23 in the astern direction. The kinetic energy of the moving vessel causes sea water flowing in the longitudinal open conduit relatively into an idle secondary-nozzle member to be accelerated thereinto, causing a dissipation of vessel energy by transfer of momentum. Sea water flowing in the longitudinal open conduit and on into the enlarged inlet of an idle secondary-nozzle member also exerts substantial drag forces which help to decelerate the vessel in the direction of relative fluid flow. When ejector propulsion stagings 18-20 and 22-23 are idle while the vessel has either headway or sternway, secondary-nozzle members thereof will exert substantial braking forces which greatly assist the positive and accurate control of vessel movement. The reversible open channel ejector structure is seen to function as a reversible fluid brake or sea anchor which will rapidly decelerate a moving vessel in either the ahead or astern direction when its motive nozzles 18 and 22 are shut off.

The semi-planing hydraulic-jet propelled vessel disclosed in FIGS. 1-6 inclusive may be provided with clinker-type shell plating construction in the submerged longitudinal open conduit with considerable advantage. Shell plating which bounds ejector passage 16 would then be installed so that the trailing edge of a forward plate lapped over the forward edge of an adjacent plate, similar to the arrangement of fish scales. The effect of this clinker-type shell plating construction would be to provide a continuous series of small hydrodynamic steps through the entire boundary of the submerged longitudinal open conduit which would trap air in the small spaces adjacent the plate laps, and considerably reduce hydrodynamic drag on the semiplaning hull body. The advantages of this clinker-type shell plating construction would be especially evident if the vessel were designed to ingest air in ahead propulsion at the forward end of ejector passage 16 adjacent secondary-nozzle member 23.

Having thus described the invention what I claim as new and desire to secure by Letters Patent is:

1. A marine propelling device to facilitate ahead-andastern propulsion comprising a reversible hydraulic-jet ejector structure extending longitudinally within the hull of a marine vessel and disposed below the normal waterline so that outside waters may pass freely from one propelling end to the other of said reversible ejector structure; said reversible longitudinal ejector structure bounded by sidewalls of an open-channel conduit formed by downwardly depending chines or keels from the hull structure of said marine vessel; an oppositely directed pair of thrust-augmenting secondary-nozzle ejector stagings disposed centrally within said longitudinal open-channel conduit, and each ejector staging disposed to discharge out of the respectively adjacent propelling end of said reversible ejector structure; each ejector staging having a central motive nozzle disposed to supply high-velocity motive fluids into the central bore of at least one adjacent secondary-nozzle member; each of said secondary-nozzle members having a Substantially frusto-conical shape and disposed in tandem with respect to any other adjacently disposed secondary-nozzle member so the fluid discharge of one of said secondary-nozzle members entrains additional suction fluid from the central fluid passage of said reversible longitudinal ejector structure into the inlet of an adjacent downstream companion secondary-nozzle member; whereby suction fluids may be reversibly accelerated in either propelling direction by the alternate supply of pressurized motive fluids to motive nozzles of said oppositely-directed pair of secondary-nozzle ejector stagings; a source of pressurized motive fluid; and closed supply conduits communicating between the said source of pressurized motive fluid and each of the said motive nozzles of the oppositely directed secondary-nozzle ejector stagings; the entire assemblage comprising a reversible hydraulic-jet ejector structure.

2. The reversible hydraulic-jet ejector structure for marine propulsion of claim 1 wherein a steering nozzle which pivots about a vertically oriented axis is disposed centrally in the said longitudinal open-channel conduit to receive inlet fluids from the direction of positive differential pressure when the vessel has headway, and to discharge a fluid jet therefrom which is angularly disposed with respect to a parallel of the longitudinal axis of said reversible ejector structure; and means for rotating the said pivoted steering nozzle about its vertically oriented axis.

3. The reversible hydraulic-jet ejector structure for marine propulsion of claim 1 wherein an intake scoop which penetrates the said bounding longitudinal openchannel conduit is disposed to receive waters exterior to the marine vessel from the direction of positive differential pressure in ahead propulsion; and said intake scoop communicates with the inlet side of a motivefluid piping system housed within said marine vessel which is disposed to alternately supply pressurized motive fluids through closed supply conduits into motive nozzles of the said pair of oppositely-directed secondary-nozzle ejector stagings.

4. The reversible hydraulic-jet ejector structure for marine propulsion of claim 1 wherein the suction of a liquid pump housed within the marine vessel communicates with waters exterior to said marine vessel; and the said liquid pump is disposed to alternately supply pressurized motive water through closed supply conduits into motive nozzles of the said pair of oppositely directed secondary-nozzle ejector stagings.

5. The reversible hydraulic-jet ejector structure for marine propulsion of claim 1 wherein a liquid pump housed within the marine vessel is disposed to receive waters exterior to said marine vessel from the direction of positive differential pressure by way of an intake scoop which penetrates the said bounding longitudinal open conduit and communicates with the suction of 1 said liquid pump; and the said liquid pump is disposed to alternately supply pressurized motive water'through closed supply conduits into motive nozzles of the said pair of oppositely-directed secondary-nozzle ejector stagings.

6. The reversible hydraulic-jet ejector structure for marine propulsion of claim 1 wherein a steam generator housed within the marine vessel is disposed to receive waters exterior to said marine vessel from a feed system which communicates with said exterior waters; and the said steam generator is disposed to alternately supply pressurized motive steam through closed supply conduits into motive nozzles of the said pair of oppositely directed secondary-nozzle ejector stagings.

7. The reversible hydraulic-jet ejector structure for marine propulsion of claim 1 wherein a steam generator housed within the marine vessel is disposed to receive waters exterior to said marine vessel from the direction of positive differential pressure by way of an intake scoop which penetrates the said bounding longitudinal conduit and communicates with the feed system of said steam generator member; and the said steam generator is disposed to alternately supply pressurized motive steam through closed supply conduits into motive nozzles of the said pair of oppositely-directed secondary-nozzle ejector stagings.

8. The reversible hydraulic-jet ejector structure for marine propulsion of claim 1 wherein a steam generator housed within the marine vessel is disposed to supply pressurized steam through closed conduit into the interior of a displacement pressure vessel; a displacement pressure vessel is disposed to receive waters exterior to said marine vessel through filling conduit which communicates therebetween; and the said displacement pressure vessel is disposed to alternately supply pressurized motive fluids through closed conduits into motive nozzles of the said pair of oppositely-directed secondary-nozzle ejector stagings.

9. The reversible hydraulic-jet ejector structure for marine propulsion of claim 1 wherein a steam generator housed within the marine vessel is disposed to supply pressurized steam through closed conduit into the interior of a displacement pressure vessel; a displacement pressure vessel is disposed to receive waters exterior to said marine vessel from the direction of positive differential pressure in ahead propulsion by way of an intake scoop which penetrates the said bounding longitudinal conduit; filling conduit which communicates between the said displacement pressure vessel and the said intake scoop; and the said displacement pressure vessel is disposed to alternately supply pressurized motive fluids through closed conduits into motive nozzles of the said pair of oppositely directed secondary-nozzle ejector stagings.

10. A hydraulic-jet propulsion system for marine vessels comprising in combination: a steam-actuated displacement pressure vessel disposed to receive waters exterior to the marine vessel; filling conduit communicating between said exterior waters and the interior of said displacement pressure vessel; valve means in the filling conduit of said displacement pressure vessel whereby the said exterior waters may be selectively admitted thereinto; a source of pressurized steam; steam supply conduit communicating between the said source of pressurized steam and the interior of said displacement pressure vessel; valve means in the said steam supply conduit whereby pressurized steam may be selectively admitted into the interior of said displacement pressure vessel to act against and eject the said exterior waters therefrom; a propulsion nozzle disposed to discharge motive fluids at an augmented velocity from said hydraulic-jet propulsion system; discharge conduit communicating between the inlet of said propulsion nozzle and the interior of said displacement pressure vessel whereby pressurized motive fluids may be supplied to the said propulsion nozzle; and valve means in the said discharge conduit whereby the said displacement pressure vessel may be selectively discharged.

11. The hydraulic-jet propulsion system for marine vessels of claim wherein an intake scoop is disposed to receive waters exterior to the marine vessel from the direction of positive differential pressure in ahead propulsion; and the said intake scoop communicates with the filling conduit of the said displacement pressure vessel.

12. The hydraulic-jet propulsion system for marine vessels of claim 10 wherein jet-spray apparatus is disposed within the interior of said displacement pressure vessel; 2. source of pressurized cooling water; cooling water conduit communicating between the said source of pressurized cooling water and the interior jet-spray apparatus of said displacement pressure vessel; and valve means in the said cooling water conduit whereby condensing cooling water may be selectively admitted into the interior of said displacement pressure vessel.

13. The hydraulic-jet propulsion system for marine vessels of claim 10 wherein an individual supply conduit for each member of an oppositely-directed pair of propulsion nozzles communicate with the discharge of said displacement pressure vessel; and valve means in each of the said nozzle supply conduits whereby pressurized motive fluids may be selectively admitted thereinto.

14. The hydraulic-jet propulsion system for marine vessels of claim 10 wherein a plurality of displacement pressure vessels are disposed in parallel with respect to each other; members of the said plurality of displacement pressure vessels are disposed to supply pressurized motive fluids through closed discharge conduit to individual nozzle supply conduits of an oppositelydirected pair of propulsion nozzles; and valve means in each of the said nozzle supply conduits whereby pressurized motive fluids may be selectively admitted thereinto.

15. A generating steam-jet propulsion system for marine vessels comprising in combination: a saline evaporator disposed to receive and evaporate waters exterior to the marine vessel; feed supply conduit communicating between said exterior waters and the interior of said saline evaporator; a feed pump disposed in the said feed supply conduit to discharge pressurized exterior feed waters into said saline evaporator; valve means in the feed supply conduit of said saline evaporator whereby the said exterior waters may be selectively admitted thereinto; a high-temperature heat exchanger acting as the heat source for the steam generating process a circulating pump for transferring cooled liquid metals to the said high-temperature heat exchanger; suction conduit communicating between the outlet of the internal heat transfer process of said saline evaporator and the inlet of said liquid metals circulating pump; discharge conduit communicating between the outlet of the said liquid metals circulating pump and the inlet to the heating process of said hightemperature heat exchanger; supply conduit communicating between the outlet from the heating process of the said high temperature heat exchanger and the inlet to the heat transfer process of the said saline evaporator, whereby high-temperature liquid metals may be transferred thereto; saline discharge conduit communicating between the evaporation process of the said saline evaporator and waters exterior to said marine vessel; valve means in the saline discharge conduit of said saline evaporator whereby brine effluent therefrom may be selectively discharged; a propulsion nozzle disposed to discharge motive steam at an augmented velocity from said steam-jet propulsion system; steam supply conduit communicating between the inlet of said propulsion nozzle and the discharge outlet of the said saline evaporator whereby pressurized motive steam may be supplied to the said propulsion nozzle; and valve means in the steam supply conduit of the said propulsion nozzle whereby the discharge of motive steam from said saline evaporator may be selectively adjusted.

16. The generating steam-jet propulsion system for marine vessels of claim 15 wherein an intake scoop is disposed to receive waters exterior to the marine vessel from the direction of positive differential pressure in ahead propulsion; and the said intake scoop communicates with the said feed supply conduit of said saline evaporator.

17. The generating steam-jet propulsion system for marine vessels of claim 15 wherein an individual supply conduit for each member of an oppositely directed pair of propulsion nozzles communicate with the said steam supply conduit and the discharge of said saline evaporator; and valve means in each of the said nozzle supply conduits whereby pressurized motive steam may be selectively admitted thereinto.

18. Reversible nozzle braking apparatus arranged longitudinally within the hull of a marine vessel and disposed below the normal waterline so that outside waters may pass from one end to the other of said nozzle braking apparatus; said nozzle braking apparatus bounded by the sidewalls of a longitudinal openchannel conduit formed into the hull structure of said marine vessel; an oppositely directed pair of nozzle brakes each composed of one or more secondarynozzle members having substantially frusto-conical shape; each nozzle brake centrally disposed within boundaries of said longitudinal open conduit to discharge out of the respectively adjacent ends thereof; each secondary-nozzle member of the said pair of oppositely directed nozzle brakes being disposed in tandem with respect to any other adjacently disposed secondary-nozzle member so the fluid discharge jet of an upstream secondary-nozzle member entrains additional suction fluid into the enlarged inlet of a downstream secondary-nozzle member; whereby momentum of a moving vessel may be partially transferred to outside waters accelerated through secondary-nozzle members of either of the said pair of oppositely directed nozzle brakes; the entire assemblage comprising a reversible open-channel nozzle brake for marine applications.

' I UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,779,200 Dated December 18, 1973 1nven or FRANCIS R, HULL It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

IN THE SPECIFICATION:

Column 1 Line 5, change "1951" to --l957---. Line 46, after "propulsion" cancel --the term---. Line 47, before open conduit insert ---The term--. Line 59, after "vessels;" cancel ---structure with--. Line 60, cancel "advantage".

Column 5 Line 57, cancel "downwardly depending". Line 58, after "boundaries of" insert --downwardly depending-- Column 7 Line 49, cancel "which is discharging".

Line 50, before "communicates" insert ---which-- Column 10 v Line 12, change "astern" to ---ahead--- IN THE CLAIMS:

Column I3, Claim 15:

Line 51, after "cess" insert Column 14, Claim 17:

Line 30, change "communicate" to ---communicates--.

Signed and sealed this 2nd day of Julyl974.

(SEAL) Attest EDWARD M. FLETCHER,JR. C.MARSH1 \LL DANN Attesting Officer Commissioner of Patents FORM PO-1 (10-69) USCOMM-DC 60376-P69 9 U.S. GOVERNMENT PRINTING OFFICE: I969 0-365-334, 

1. A marine propelling device to facilitate ahead-and-astern propulsion comprising a reversible hydraulic-jet ejector structure extending longitudinally within the hull of a marine vessel and disposed below the normal waterline so that outside waters may pass freely from one propelling end to the other of said reversible ejector structure; said reversible longitudinal ejector structure bounded by sidewalls of an open-channel conduit formed by downwardly depending chines or keels from the hull structure of said marine vessel; an oppositely directed pair of thrust-augmenting secondary-nozzle ejector stagings disposed centrally within said longitudinal open-channel conduit, and each ejector staging disposed to discharge out of the respectively adjacent propelling end of said reversible ejector structure; each ejector staging having a central motive nozzle disposed to supply high-velocity motive fluids into the central bore of at least one adjacent secondary-nozzle member; each of said secondary-nozzle members having a substantially frusto-conical shape and disposed in tandem with respect to any other adjacently disposed secondary-nozzle member so the fluid discharge of one of said secondary-nozzle members entrains additional suction fluid from the central fluid passage of said reversible longitudinal ejector structure into the inlet of an adjacent downstream companion secondary-nozzle member; whereby suction fluids may be reversibly accelerated in either propelling direction by the alternate supply of pressurized motive fluids to motive nozzles of said oppositely-directed pair of secondary-nozzle ejector stagings; a source of pressurized motive fluid; and closed supply conduits communicating between the said source of pressurized motive fluid and each of the said motive nozzles of the oppositely directed secondary-nozzle ejector stagings; the entire assemblage comprising a reversible hydraulic-jet ejector structure.
 2. The reversible hydraulic-jet ejector structure for marine propulsion of claim 1 wherein a steering nozzle which pivots about a vertically oriented axis is disposed centrally in the said longitudinal open-channel conduit to receive inlet fluids from the direction of positive differential pressure when the vessel has headway, and to discharge a fluid jet therefrom which is angularly disposed with respect to a parallel of the longitudinal axis of said reversible ejector structure; and means for rotating the said pivoted steering nozzle about its vertically oriented axis.
 3. The reversible hydraulic-jet ejector structure for marine propulsion of claim 1 wherein an intake scoop which penetrates the said bounding longitudinal open-channel conduit is disposed to receive waters exterior to the marine vessel from the direction of positive differential pressure in ahead propulsion; and said intake scoop communicates with the inlet side of a motive-fluid piping system housed within said marine vessel which is disposed to alternately supply pressurized motive fluids through closed supply conduits into motive nozzles of the said pair of oppositely-directed secondary-nozzle ejector stagings.
 4. The reversible hydraulic-jet ejector structure for marine propulsion of claim 1 wherein the suction of a liquid pump housed within the marine vessel communicates with waters exterior to said marine vessel; and the said liquid pump is disposed to alternately supply pressurized motive water through closed supply conduits into motive nozzles of the said pair of oppositely directed secondary-nozzle ejector stagings.
 5. The reversible hydraulic-jet ejector structure for marine propulsion of claim 1 wherein a liquid pump housed within the marine vessel is disposed to receive waters exterior to said marine vessel from the direction of positive differential pressure by way of an intake scoop which penetrates the said bounding longitudinal open conduit and communicates with the suction of said liquid pump; and the said liquid pump is disposed to alternately suppLy pressurized motive water through closed supply conduits into motive nozzles of the said pair of oppositely-directed secondary-nozzle ejector stagings.
 6. The reversible hydraulic-jet ejector structure for marine propulsion of claim 1 wherein a steam generator housed within the marine vessel is disposed to receive waters exterior to said marine vessel from a feed system which communicates with said exterior waters; and the said steam generator is disposed to alternately supply pressurized motive steam through closed supply conduits into motive nozzles of the said pair of oppositely directed secondary-nozzle ejector stagings.
 7. The reversible hydraulic-jet ejector structure for marine propulsion of claim 1 wherein a steam generator housed within the marine vessel is disposed to receive waters exterior to said marine vessel from the direction of positive differential pressure by way of an intake scoop which penetrates the said bounding longitudinal conduit and communicates with the feed system of said steam generator member; and the said steam generator is disposed to alternately supply pressurized motive steam through closed supply conduits into motive nozzles of the said pair of oppositely-directed secondary-nozzle ejector stagings.
 8. The reversible hydraulic-jet ejector structure for marine propulsion of claim 1 wherein a steam generator housed within the marine vessel is disposed to supply pressurized steam through closed conduit into the interior of a displacement pressure vessel; a displacement pressure vessel is disposed to receive waters exterior to said marine vessel through filling conduit which communicates therebetween; and the said displacement pressure vessel is disposed to alternately supply pressurized motive fluids through closed conduits into motive nozzles of the said pair of oppositely-directed secondary-nozzle ejector stagings.
 9. The reversible hydraulic-jet ejector structure for marine propulsion of claim 1 wherein a steam generator housed within the marine vessel is disposed to supply pressurized steam through closed conduit into the interior of a displacement pressure vessel; a displacement pressure vessel is disposed to receive waters exterior to said marine vessel from the direction of positive differential pressure in ahead propulsion by way of an intake scoop which penetrates the said bounding longitudinal conduit; filling conduit which communicates between the said displacement pressure vessel and the said intake scoop; and the said displacement pressure vessel is disposed to alternately supply pressurized motive fluids through closed conduits into motive nozzles of the said pair of oppositely directed secondary-nozzle ejector stagings.
 10. A hydraulic-jet propulsion system for marine vessels comprising in combination: a steam-actuated displacement pressure vessel disposed to receive waters exterior to the marine vessel; filling conduit communicating between said exterior waters and the interior of said displacement pressure vessel; valve means in the filling conduit of said displacement pressure vessel whereby the said exterior waters may be selectively admitted thereinto; a source of pressurized steam; steam supply conduit communicating between the said source of pressurized steam and the interior of said displacement pressure vessel; valve means in the said steam supply conduit whereby pressurized steam may be selectively admitted into the interior of said displacement pressure vessel to act against and eject the said exterior waters therefrom; a propulsion nozzle disposed to discharge motive fluids at an augmented velocity from said hydraulic-jet propulsion system; discharge conduit communicating between the inlet of said propulsion nozzle and the interior of said displacement pressure vessel whereby pressurized motive fluids may be supplied to the said propulsion nozzle; and valve means in the said discharge conduit whereby the said displacement pressure vessel may be selectively discharged.
 11. The hydraulic-jet Propulsion system for marine vessels of claim 10 wherein an intake scoop is disposed to receive waters exterior to the marine vessel from the direction of positive differential pressure in ahead propulsion; and the said intake scoop communicates with the filling conduit of the said displacement pressure vessel.
 12. The hydraulic-jet propulsion system for marine vessels of claim 10 wherein jet-spray apparatus is disposed within the interior of said displacement pressure vessel; a source of pressurized cooling water; cooling water conduit communicating between the said source of pressurized cooling water and the interior jet-spray apparatus of said displacement pressure vessel; and valve means in the said cooling water conduit whereby condensing cooling water may be selectively admitted into the interior of said displacement pressure vessel.
 13. The hydraulic-jet propulsion system for marine vessels of claim 10 wherein an individual supply conduit for each member of an oppositely-directed pair of propulsion nozzles communicate with the discharge of said displacement pressure vessel; and valve means in each of the said nozzle supply conduits whereby pressurized motive fluids may be selectively admitted thereinto.
 14. The hydraulic-jet propulsion system for marine vessels of claim 10 wherein a plurality of displacement pressure vessels are disposed in parallel with respect to each other; members of the said plurality of displacement pressure vessels are disposed to supply pressurized motive fluids through closed discharge conduit to individual nozzle supply conduits of an oppositely-directed pair of propulsion nozzles; and valve means in each of the said nozzle supply conduits whereby pressurized motive fluids may be selectively admitted thereinto.
 15. A generating steam-jet propulsion system for marine vessels comprising in combination: a saline evaporator disposed to receive and evaporate waters exterior to the marine vessel; feed supply conduit communicating between said exterior waters and the interior of said saline evaporator; a feed pump disposed in the said feed supply conduit to discharge pressurized exterior feed waters into said saline evaporator; valve means in the feed supply conduit of said saline evaporator whereby the said exterior waters may be selectively admitted thereinto; a high-temperature heat exchanger acting as the heat source for the steam generating process a circulating pump for transferring cooled liquid metals to the said high-temperature heat exchanger; suction conduit communicating between the outlet of the internal heat transfer process of said saline evaporator and the inlet of said liquid metals circulating pump; discharge conduit communicating between the outlet of the said liquid metals circulating pump and the inlet to the heating process of said high-temperature heat exchanger; supply conduit communicating between the outlet from the heating process of the said high temperature heat exchanger and the inlet to the heat transfer process of the said saline evaporator, whereby high-temperature liquid metals may be transferred thereto; saline discharge conduit communicating between the evaporation process of the said saline evaporator and waters exterior to said marine vessel; valve means in the saline discharge conduit of said saline evaporator whereby brine effluent therefrom may be selectively discharged; a propulsion nozzle disposed to discharge motive steam at an augmented velocity from said steam-jet propulsion system; steam supply conduit communicating between the inlet of said propulsion nozzle and the discharge outlet of the said saline evaporator whereby pressurized motive steam may be supplied to the said propulsion nozzle; and valve means in the steam supply conduit of the said propulsion nozzle whereby the discharge of motive steam from said saline evaporator may be selectively adjusted.
 16. The generating steam-jet propulsion system for marine vessels of claim 15 wherein an intake scoop is disposed to receive waters Exterior to the marine vessel from the direction of positive differential pressure in ahead propulsion; and the said intake scoop communicates with the said feed supply conduit of said saline evaporator.
 17. The generating steam-jet propulsion system for marine vessels of claim 15 wherein an individual supply conduit for each member of an oppositely directed pair of propulsion nozzles communicate with the said steam supply conduit and the discharge of said saline evaporator; and valve means in each of the said nozzle supply conduits whereby pressurized motive steam may be selectively admitted thereinto.
 18. Reversible nozzle braking apparatus arranged longitudinally within the hull of a marine vessel and disposed below the normal waterline so that outside waters may pass from one end to the other of said nozzle braking apparatus; said nozzle braking apparatus bounded by the sidewalls of a longitudinal open-channel conduit formed into the hull structure of said marine vessel; an oppositely directed pair of nozzle brakes each composed of one or more secondary-nozzle members having substantially frusto-conical shape; each nozzle brake centrally disposed within boundaries of said longitudinal open conduit to discharge out of the respectively adjacent ends thereof; each secondary-nozzle member of the said pair of oppositely directed nozzle brakes being disposed in tandem with respect to any other adjacently disposed secondary-nozzle member so the fluid discharge jet of an upstream secondary-nozzle member entrains additional suction fluid into the enlarged inlet of a downstream secondary-nozzle member; whereby momentum of a moving vessel may be partially transferred to outside waters accelerated through secondary-nozzle members of either of the said pair of oppositely directed nozzle brakes; the entire assemblage comprising a reversible open-channel nozzle brake for marine applications. 